Silicone Rubber Research Articles

Coupling of Aging Mechanism and Lifetime Prediction for Silicone Rubber Bonding Structure over MD Simulation

Coupling of Aging Mechanism and Lifetime Prediction for Silicone Rubber Bonding Structure over MD Simulation

Understanding the impact of different nanofillers on electrical, thermal, and surface properties of corona‐aged silicone rubber nanocomposites

Understanding the impact of different nanofillers on electrical, thermal, and surface properties of corona‐aged silicone rubber nanocomposites

Simulation-Directed Construction of Bamboo-Forest-Like Heat Conduction Networks to Enhance Silicon Rubber Composites' Heat Conduction Properties.

Highly vertically thermally conductive silicon rubber (SiR) composites are widely used as thermal interface materials (TIMs) for chip cooling. Herein, inspired by water transport and transpiration of Moso bamboo-forests extensively existing in south China, and guided by filler self-assembly simulation, bamboo-forest-like heat conduction networks, with bamboo-stems-like vertically aligned polydopamine-coated carbon fibers (VA-PCFs), and bamboo-leaves-like horizontally layered Al2O3(HL-Al2O3), are rationally designed and constructed. VA-PCF/HL-Al2O3/SiR composites demonstrated enhanced heat conduction properties, and their through-plane thermal conductivity and thermal diffusivity reached 6.47W(mK)-1 and 3.98mm2s-1 at 12vol% PCF and 4vol% Al2O3 loadings, which are 32% and 38% higher than those of VA-PCF (12vol%) /SiR composites, respectively. The heat conduction enhancement mechanisms of VA-PCF/HL-Al2O3 networks on their SiR composites are revealed by multiscale simulation: HL-Al2O3 bridges the separate VA-PCF heat flow channels, and transfers more heat to the matrix, thereby increasing the vertical heat flux in composites. Along with high volume resistivity, low compression modulus, and coefficient of thermal expansion, VA-PCF/HL-Al2O3/SiR composites demonstrate great application potential as TIMs, which is proven using multiphysics simulation. This work not only makes a meaningful attempt at simulation-driven biomimetic material structure design but also provides inspiration for the preparation of TIMs.

Multifunctional elastomer-organohydrogel hybrid patch for durable skin epidermal strain-sensing and antibacterial applications

A multifunctional elastomer-organohydrogel hybrid patch for skin surface strain sensors, denoted as MSR-PO, composed of a modified conductive silicone rubber (MSR) and PAA-based organohydrogel (PO), is fabricated by surface radical polymerization of the PO layer on MSR film, the two layers are linked together with the strong chemical bonding, thereby amalgamating their distinct functionalities. The MSR layer endows the patch with great wear-resisting, anti-freezing, and durable sensing properties. The gel layer coated on conductive silicone rubber imparts the patch with excellent adhesive capability to match the modulus of the skin, which is in favor of monitoring large and small movements of the human body, showing great potential in the field of wearable flexible electronic sensing. Importantly, the rubber layer and gel layer of MSR-PO patch exhibit outstanding synergistic antibacterial effects. This work will inspire the design and fabrication of novel rubber-gel asymmetric patch for multifunctional applications.

Effect of iron‐containing fillers on heat release kinetics and strength properties of polyester resin

AbstractThe influence of filling by iron‐containing fillers on the heat release kinetics and mechanical properties of industrial unsaturated polyester resin PN‐1 is investigated experimentally. The iron ore concentrate, electrostatic precipitator dust, high alumina cement grade HAC‐1, shavings made of cast iron, fine grade sand are used as fillers. To improve the strength characteristics of polyester resin composites the small amount (0.2–1.0 wt%) of organosilicon additives such as synthetic silicone rubber, tris(trimethylsiloxy) phenylsilane, octamethyl cyclotetrasiloxane are used. The heat release kinetics is studied for different ratios between accelerator (cobalt naphthenate) and initiator (cyclohexanone peroxide). The time to reach the maximum temperature of the heat release is significantly reduced when a large amount of iron ore concentrate is used as filler. The temperature of maximum heat release decreases and the time to reach it increases when adding electrostatic precipitator dust in small amount of 5 wt% to the high filled by iron ore concentrate (295 wt%) composite system. The optimum in strength indicators associated with the ratio of different fractions in systems consisting of two fillers of different properties and granulometric composition is found. The highest values of compressive strength in the cement–iron ore concentrate and sand–iron ore concentrate systems are observed. An increase in the strength characteristics of composites by 15%–20% with organosilicon additive introduction is observed. The addition of the silicone rubber increases the strength properties of samples the most among all additives considered.Highlights Effect of filling by iron‐containing fillers on the heat release kinetics and mechanical properties of polyester resin is found. The time to reach the maximum temperature of the heat release is significantly reduced when the resin is filled by a large amount of iron ore concentrate. The temperature of maximum heat release decreases when the electrostatic precipitator dust in small amount is added to the high filled by iron ore concentrate. An increase in the strength characteristics of composites by 15–20% with introduction of organosilicon additives is observed.

Fluorinated boron nitride nanosheets for high thermal conductivity and low dielectric constant silicone rubber composites

AbstractIncreasing miniaturization and integration of microelectronic devices have led to an unprecedented attention on heat dissipation and signal transmission of electronic equipment. However, the mostly used method to enhance the thermal conductivity of polymers by adding thermally conductive fillers usually results in the increase of dielectric constant (Dk). It was still challenging to synergistically achieve low Dk and high thermal conductivity of polymer‐matrix composites. Herein, hydroxylated boron nitride nanosheet (BNNS‐OH) with a high yield of 35.67% was prepared by the liquid ultrasonic exfoliation under the assistance of sodium cholate (SC), and grafted with (1H,1H,2H,2H‐perfluorodecyl) trimethoxy silane to prepare fluorinated boron nitride nanosheets (F‐BNNS), which can uniformly disperse in liquid silicone rubber (LSR) and reduce the Dk of LSR composites. The thermal conductivity of LSR composites with 20 wt% F‐BNNS reached 0.489 W·m−1·K−1, showing an increase of 307.35% in comparison with pure LSR (0.12 W·m−1·K−1). Meantime, the Dk of as‐obtained LSR/F‐BNNS (20 wt%) composites is reduced from 3.4 to 2.6, and the dielectric loss (Df) is less than 0.012. The facile and rational design of fluorinated BNNS offers a new insight for the high‐end electronic packaging materials.Highlights A new method of exfoliation and fluorinated treatment of h‐BN was proposed. The LSR composites achieved an ultralow Dk of 2.63 via fluorinated BNNS. Thermal conductivity of LSR composites increased by 307.35% than pure LSR.

Effect of Interface Defects on the Electric–Thermal–Stress Coupling Field Distribution of Cable Accessory Insulation

The combined insulation interface of a high-voltage cable and accessories is the weakest part of a cable system. In this paper, the parameters of the dielectric constant, thermal conductivity, and elastic modulus of cross-linked polyethylene (XLPE) and silicone rubber (SIR) are obtained experimentally. On this basis, the model of a specific type of 110 kV cable and prefabricated insulation joint is established. A simulation of the electric–thermal–stress coupling field in the presence of typical defects in the main insulation–inner semi-conductive (SEMI) shielding layer (XLPE/SEMI interface) and the main insulation–silicone rubber insulation layer (XLPE/SIR interface) is studied. The simulation results show that at the XLPE/SIR interface, the electric field distortion caused by bubble defects reached 20.17 kV/mm, and the temperature rose to 56.15 °C. The effect of air-gap defects on the interface is similar to that of bubble defects. In addition, the semi-conductive impurity defects induced an increase in temperature to 56.82 °C and an increase in stress to 0.32 MPa. At the XLPE/SEMI interface, the electric field distortion induced by bubble defects was 19.98 kV/mm, and the temperature rose to 61.72 °C. The electric field distortion caused by metallic and semi-conductive defects was 8.44 kV/mm and 8.64 kV/mm, respectively. This study serves as a reference for the fault analysis and the operation and maintenance of cable accessories.

Novel fillers for wearable technology: Impact of titanium carbide and thinners on room temperature vulcanized silicone rubber composites

Wearable technology has emerged as a robust pathway to achieve smart functionalities in healthcare, sports, fitness, and beyond. This study investigates the mechanical and electromechanical properties of silicone rubber (SR) composites. The SR was reinforced with titanium carbide (TiC) and modified with varying (room-temperature vulcanized) RTV-thinner (silicone oil) concentrations. RTV-SR was utilized, which cures at room temperature to form a flexible, durable, and moldable rubber widely used for sealing, bonding, and making molds. The addition of TiC enhanced tensile strength from 0.5 MPa (control) to 0.59 MPa (5 phr of TiC), and tensile modulus from 0.41 MPa to 0.51 MPa. However, the thinner inclusion reduced tensile properties. For instance, the T10 sample (10 phr thinner) showed a tensile strength of 0.51 MPa and a tensile modulus of 0.29 MPa making the composites soft. Thinner addition also increased ductility, with fracture strains rising from 151 % (control) to 217 % (T10). Compressive strength followed a similar trend, with the control and 5 phr TiC samples exhibiting compressive strengths of 0.18 MPa and 0.17 MPa, respectively, which decreased to 0.12 MPa for the T20 sample. Under cyclic loading, TiC-filled samples showed consistent load patterns, while thinner addition resulted in increased energy dissipation and reduced stiffness. Electromechanical analysis revealed that TiC 5 phr samples exhibited stable piezoelectric responses, with voltage outputs increasing from ±0.1 mV at 15 % strain to ±1.0 mV at 40 % strain. The T5 samples demonstrated significant voltage improvements, generating ±2.5 mV at 15 % strain and ±5 mV at 40 % strain. Long-term cyclic tests confirmed the stability of T5 samples, maintaining voltage outputs of −1.5 mV to 1.5 mV over 50 minutes. Response time analysis indicated faster response times for TiC 5 phr samples, decreasing from 145 ms at 15 % strain to 102 ms at 40 % strain, while thinner addition led to longer response times. Real-time electromechanical tests under mechanical study showed that T5 samples achieved optimal performance with voltage peaks up to ±2.4 mV under thumb pressing. These findings highlight the trade-off between mechanical strength and flexibility, suggesting that an optimal balance of TiC and thinner enhances the properties of silicone rubber composites for applications in wearable technology and sensors.

Synthesis and characterization of MWCNTs nanocomposite for fabrication of tensometric transducers

A nanocomposite was prepared using MWCNTs and micro-sized bronze particles dispersed in elastomer silicone organic compound (SILAGER 8030). The nano-composite was characterized by FT-IR, SEM, EDS and Raman spectroscopy; showing the rough surface of the composite with interweaving of nano threads. This nano-composite was used to manufacture strain gauge. The conductivities were measured concerning wt% of micro-sized bronze, compression and time. The maximum electrical conductivity obtained was 2.1 S/m at 5.0 wt% bronze metal alloy and MWCNT (3.0 wt%) at 16% compression. With increasing amplitude and frequency of ultrasonic exposure, an increase in the pressure associated with cavitation in the liquid was observed. Each value of ultrasound exposure corresponded to a certain value of electrical resistance. At the same time, with an increase in the intensity of the cavitation effect on the strain gauge transducer, extremum points appeared, which corresponded to a decrease in resistance. The developed material is highly useful for manufacturing strain gauges to be used in liquid ring vacuum pumps as a measuring transducer of liquid ring pressure into signals associated with changes in resistance. This allows liquid ring vacuum pumps to be precisely controlled; improving their energy efficiency and reliability.

The cross-sectional geometry regulated Poynting effect in ribbed silicone rubber tubes

The cross-sectional geometry regulated Poynting effect in ribbed silicone rubber tubes

Rapid and Cost-Effective Fabrication and Performance Evaluation of Force-Sensing Resistor Sensors

In this study, we developed a cost-effective and rapid method for fabricating force-sensing resistor (FSR) sensors as an alternative to commercial force sensors. Our aim was to achieve performance characteristics comparable to existing commercial products while significantly reducing costs and fabrication time. We analyzed the material composition of two widely used commercial force sensors: Interlink FSR-402 and Flexiforce A201-1. Based on this analysis, we selected 4B and 9B pencils, which contain high concentrations of graphite, and silicone sealant to replicate these material properties. The fabrication process involved creating piezoresistive sheets by shading A4 copy paper with 4B and 9B pencils to form a uniform layer of graphite. Additionally, we prepared a mixture of 9B pencil lead powder and silicone sealant, ensuring a consistent application on the paper substrate. Measurement results indicated that the force sensor fabricated using a mixture of 9B pencil powder and silicone sealant exhibited electrical and mechanical characteristics closely resembling those of commercial sensors. Load tests revealed that the hand-made sensors provided a proportional voltage output in response to increasing and decreasing loads, similar to commercial FSR sensors. These results suggest that our fabrication method can produce reliable and accurate FSR sensors suitable for various applications, including wearable technology, robotics, and force-sensing interfaces. Overall, this study demonstrates the potential for creating cost-effective and high-performance FSR sensors using readily available materials and simple fabrication techniques.

Analytical model of friction at low shear rates for soft materials in 3D printing.

The biological properties of silicone elastomers such as polydimethylsiloxane (PDMS) have widespread use in biomedicine for soft tissue implants, contact lenses, soft robots, and many other small medical devices, due to its exceptional biocompatibility. Additive manufacturing of soft materials still has significant challenges even with major advancements that have occurred in development of these technologies for customized medical devices and tissue engineering. The aim of this study was to develop a mathematical model of tangential stress in relation to shear stress, shear rate, 3D printing pressure and velocity, for non-Newtonian gels and fluids that are used as materials for 3D printing. This study used FENE (finitely extensible nonlinear elastic model) model, for non-Newtonian gels and fluids to define the dependences between tangential stress, velocity, and pressure, considering viscosity, shear stress and shear rates as governing factors in soft materials friction and adhesion. Experimental samples were fabricated as showcases, by SLA and FDM 3D printing technologies: elastic polymer samples with properties resembling elastic properties of PDMS and thermoplastic polyurethane (TPU) samples. Experimental 3D printing parameters were used in the developed analytical solution to analyse the relationships between governing influential factors (tangential stress, printing pressure, printing speed, shear rate and friction coefficient). Maple software was used for numerical modelling. Analytical model applied on a printed elastic polymer, at low shear rates, exhibited numerical values of tangential stress of 0.208-0.216 N m - 2 at printing velocities of 0.9 to 1.2 mm s - 1, while the coefficient of friction was as low as 0.09-0.16. These values were in accordance with experimental data in literature. Printing pressure did not significantly influence tangential stress, whereas it was slightly influenced by shear rate changes. Friction coefficient linearly increased with tangential stress. Simple analytical model of friction for elastic polymer in SLA 3D printing showed good correspondence with experimental literature data for low shear rates, thus indicating possibility to use it for prediction of printing parameters towards desired dimensional accuracy of printed objects. Further development of this analytical model should enable other shear rate regimes, as well as additional soft materials and printing parameters.

Bioinspired Functional Composites for Enhanced Thermally Conductivity via Fractal-Growth CuNP Fillers.

Thermal conduction for electronic devices has attracted extensive attention in light of the development of 5G communication. Thermally conductive materials with high thermal conductivity and extensive mechanical flexibility are extremely desirable in practical applications. However, the construction of efficient interconnected conductive pathways and continuous conductive networks is inadequate for either processing or actual usage in existing technologies. In this work, spherical copper nanoparticles (S-CuNPs) and urchin-inspired fractal-growth CuNPs (U-CuNPs), thermally conductive metal fillers induced by ionic liquids, were fabricated successfully through the electrochemical deposition method. Compared to S-CuNPs, the U-CuNPs shows larger specific surface contact area, thus making it easier to build a continuous conductive pathway network in the corresponding U-CuNPs/liquid silicone rubber (LSR) thermally conductive composites. The optimal loading of CuNP fillers was determined by evaluating the rheological performance of the prepolymer and the mechanical properties and thermal conductivity performances of the composites. When the filler loading is 150 phr, the U-CuNPs/LSR produces optimal mechanical properties (e.g., tensile strength and modulus), thermal conductivity (above 1000% improvement compared to pure LSR), and heating/cooling efficiency. The enhanced thermal conductivity of U-CuNPs/LSR was also confirmed through the finite element analysis (FEA) overall temperature distribution, indicating that U-CuNPs with larger specific surface contact areas exhibit more advantages in forming a continuous network in composites than S-CuNPs, making U-CuNPs/LSR a promising and competitive alternative to traditional flexible thermally interface materials.

Development of a large diameter invitro flow loop thrombogenicity test system.

To accommodate a wider range of medical device sizes, a larger invitro flow loop thrombogenicity test system using 9.5 -mm inner diameter (ID) tubing was developed and evaluated based on our previously established 6.4 -mm ID tubing system. Four cardiopulmonary bypass roller pumps were used concurrently to drive four flow loops during testing. To ensure that each pump produced a consistent thrombogenic response for the same material under the same test conditions, a novel dynamic roller occlusion setting method was applied. Five materials with varying thrombogenic potentials were tested: polytetrafluoroethylene (PTFE), silicone, 3D-printed nylon, latex, and nitrile rubber (BUNA). Day-old bovine blood was heparinized to a donor-specific concentration and recirculated through the flow loops containing test materials at 20 rpm for 1 h at room temperature. Material thrombogenicity was characterized by measuring the thrombus surface coverage, thrombus weight, and platelet (PLT) count reduction. The larger tubing system can differentiate thrombogenic materials (latex, BUNA) from the thromboresistant PTFE material. Additionally, silicone and the 3D-printed nylon exhibited an intermediate thrombogenic response with significantly less thrombus surface coverage and PLT count reduction than latex and BUNA but more thrombus surface coverage than PTFE (p < 0.05). The 9.5 -mm ID test system can effectively differentiate materials of varying thrombogenic potentials when appropriate pump occlusion settings and donor-specific anticoagulation are used. This system is being assessed in an interlaboratory study to develop standardized best practices for performing invitro dynamic thrombogenicity testing of medical devices and materials.

Innovative radiation shielding material with flexible lightweight and low cost from shrimp shells waste

This study explores an innovative approach to developing radiation shielding materials using shrimp shell waste. The research investigates the feasibility of incorporating shrimp shells into a silicone rubber matrix to create a flexible, lightweight, and cost-effective radiation shielding material. Shrimp shells, rich in calcium carbonate (CaCO3) content of 13.90%, offers promising properties for radiation attenuation. Through a series of experiments and characterization techniques, including X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), the effectiveness of the composite material in attenuating radiation is evaluated. The results demonstrate that as the shrimp shell concentration rose from 25% to 75%, the absorbed radiation increased from 9.27% to 82.39% (40 kVp) and from 1.88% to 30.22% (120 kVp), while the linear coefficient also increased, attributed to the presence of CaCO3. This novel radiation shielding material presents a sustainable solution by repurposing shrimp shell waste while offering a flexible, lightweight, and cost-effective shielding for various radiation applications.

Study on powdering properties of silicone rubber insulating material in a coastal area

Abstract Silicone rubber insulation materials are widely used in energy systems. The powdering of silicone rubber sheds is a newly discovered aging phenomenon in recent years, and there is no specific research. In this paper, the powder composition of the composite insulators in coastal areas was studied, and the powdering process of silicone rubber under a high humidity environment of salt fog was repeated in the laboratory. The results show that the powders can be divided into two types according to particle shape, element composition, and molecule groups: the inorganic filler and its dehydrated product and the small molecule siloxane after polymer aging fracture. The particle size of Type I of powder is 3∼8μm, and the particle size of Type II of small molecule siloxane is 0.3∼1.1μm. The surface hydrophobicity of the powdered sample in a salt-fog environment will deteriorate, and the static contact angle will decrease. However, the hydrophobicity will gradually recover after leaving the harsh environment. Powdering of composite insulator silicone rubber in coastal areas is a complex physical and chemical process caused by the combined action of electricity, heat, and moisture. During this, polymer molecular chains break, and fillers gradually precipitate, forming powders.

Manufacturing of Stretchable Wavy-Patterned Fiber-Reinforced Elastomer Composites and Its Behaviors Under Tensile Loading Conditions

The wavy-patterned carbon fiber reinforced elastomer composites that offered both the elongation characteristic of the elastomer and the stiffness of the fiber reinforcement before the elastomer reached its elongation at failure was introduced in this study. The goal of this study was to develop and demonstrate the manufacturing process of the wavy-patterned fiber-reinforced elastomer composites and investigate its behaviors under tensile loading conditions. A carbon fiber tow was impregnated with a silicone elastomer and placed in the test specimen manufacturing mold with a specific pattern using a wavy-patterned fiber placing jig. The silicone elastomer was then poured into the mold to cast test specimens. Various wavy-patterned fiber-reinforced elastomer composites, each with different allowed elongation levels and different amount of fiber, were designed and fabricated. Due to fiber slippage during the tensile test with the traditional test grip fixture, a roller grip fixture was used for the tensile test. The test results showed a unique behavior of the wavy-patterned fiber reinforced elastomer composites that elongated until the patterned fiber became straightened, providing additional stiffness to the test specimen under tensile loading. It was observed that the maximum strength and elongation at failure varied with different patterns and amounts of fiber. The unique failure mechanisms of the fiber-reinforced elastomer composite during the tensile test were analyzed and discussed. Despite the fiber being fully impregnated with the elastomer, weak adhesion between the fiber and elastomer led to disbonding between them.

Abstract P449: A Murine Model of Mid-Thoracic Aortic Coarctation

Vascular pressure can directly affect cardiovascular structure and function. Understanding the mechanisms, however, is complicated because conditions or interventions that chronically raise blood pressure (e.g. excess angiotensin II) can also have direct effects on the vasculature that occur independent of changes in blood pressure. One approach to mitigating this problem is to obstruct flow in a vascular segment sufficiently to reduce blood pressure in the segment downstream of the obstruction, while pressure upstream either stays the same or increases. As a result, all factors other than pressure are expected to be the same in upstream and downstream vascular segments. We have found evidence that differences in intravascular pressure can also affect closely adjacent tissues, specifically perivascular adipose tissue (PVAT). To test this idea in vivo , we developed a method to produce chronic, partial occlusion (or coarctation) of the mid-thoracic aorta in mice. This exposes upstream aortic PVAT depots to significantly higher aortic pressure than downstream aortic PVAT depots. The key to the method is producing a stable occlusion with a diameter small enough to produce a pressure gradient but not so small that the downstream flow is inadequate to support tissue oxygenation. To this end, a thoracotomy was performed to expose the thoracic aorta in adult mice anesthetized with isoflurane and artificially ventilated. A coarctation of the mid-thoracic aorta was produced by tying a ligature around the aorta and a blunted needle on the aorta, then removing the needle. In other mice, a silicone rubber or nitrile O-ring of varying dimensions was placed around the aorta. Mice were allowed to recover for varying periods of time (weeks), then the degree of coarctation was evaluated using both imaging methods (ultrasound) and direct measurement of the pressure gradient (catheters placed in a carotid and a femoral artery) under isoflurane anesthesia. In a group of 9 male mice with coarctation and 4 male mice with sham coarctation, we found an average mean arterial pressure gradient of 11.7 ± 5.0 mmHg (mean ± SEM) in coarct mice and 1.6 ± 2.0 mmHg in sham mice. Systolic pressure gradients averaged 14.0 ± 5.9 mmHg in coarct mice and 1.0 ± 3.2 mmHg in sham mice. These results suggest it is possible to produce a stable pressure gradient across the thoracic aorta of mice as a tool to explore the impact of arterial pressure on vascular and PVAT structure and function.

Identification of Decedents by Restoring Mummified Fingerprints: Forensic Dermatology in the Investigation of Mummy Dermatoglyphics

Fingerprints are created by elevations and depressions on the fingertip pads. Each person has their own unique fingerprints which can be used in the identification of that individual when alive, during the immediate postmortem period, or even after the digits have become mummified. Mummification can occur naturally; it can be partial (such as localized to only the hands and feet, extensive, or complete. Obtaining fingerprints after the skin has become mummified can be attempted while the digits remaining intact with the hand; however, the digits may need to be removed from the hand and the finger pads may also need to be separated from the underlying bone to secure an adequate fingerprint. Frequently, the mummified tissue needs to be rehydrated; numerous solutions have been used that increase the turgor of the digits, provide softening and pliability of the tissue, and enhance the details of the finger pad ridges. An aqueous solution of sodium carbonate (either combined with acetic acid or combined with 95 percent ethanol and distilled water) was found to be most effective for rehydration. Thereafter, various techniques can be attempted to obtain the fingerprint. These include the traditional method of inking and rolling of the finger or photographing the finger. Powders (such as aluminum powder, black fingerprint powder, white cornstarch-based powder, or fluorescent powder) can be used to enhance the ridge features; adhesive tape can be pressed against the powdered digit and the print pattern preserved by applying the adhesive tape to a clear transparency sheet. In addition, molds (using modeling clay or silicone rubber) and casts (using plaster of Paris, dental casting materials, or putty) can be made of the digits; either the molds or the casts or both can be photographed with or without prior application of fingerprint powder. Transillumination, using a fiber optic light source to illuminate the epidermis and underlying remaining dermis of a scraped and defleshed finger pad can be used to demonstrate the finger ridge pattern when the photographing the tip of the digit. In summary, forensic dermatology can have an integral role in obtaining fingerprints from mummified digits, which can be successfully used for the identification of the decedent.

Recent development of metal-organic frameworks as a novel flame-retardant in polymeric applications

Abstract The increasing concern regarding hazardous fires related to polymeric materials has prompted numerous research into eco-friendly flame retardants. in recent years metal-organic Frameworks (MOFs) have emerged as promising flame-retardant materials, characterized by metal-containing units linked to organic linkers to create strong and porous crystalline frameworks. The organic ligands make MOFs possess significant surface area and adsorption properties desirable for different applications including flame retardancy. This paper gathers many of the recently published to discuss the use performance of polymer composites with MOFs for flame retardancy in comparison with polymeric composite materials without MOFs. Besides, a comparison based on mechanical, physical, and thermal properties shows the effect of MOF on the total effectiveness of the polymeric composite materials. This paper is of great interest to both the readers involved in the sphere of heat-resistance materials, encompassing contemporary advanced composite materials used for dampening hazardous fires. Furthermore, prospective trends, including the integration of innovative fillers such as MOFs in rubber composites such as NBR (Nitrile Butadiene Rubber), EPDM (Ethylene Propylene Diene Monomer), and silicone rubber, are deliberated upon.